Now add Toro, app-marketing software that targets Facebook users, to the mix. For an undisclosed price, Google has acquired Red Hot Labs, which created Toro to run ad campaigns for software developers who are trying to get users to download their apps, according to Google spokesperson Winnie King. The company will join Google’s mobile ads team, King wrote in an e-mail.

Google isn’t commenting on what exactly it plans to do with Toro or anything else Red Hot Labs has built. The acquired company said it will continue optimizing its existing customers’ ad campaigns, and has suspended creating new projects for customers.

“We recommend working with an alternative Facebook PMD [preferred marketing developer] for new campaigns going forward,” the company wrote on its blog, which was posted by founder and CEO Amitt Mahajan. “With greater resources and distribution now available at our disposal, we’re excited to join Google and continue our mission of making the lives of app developers easier.”

Before Red Hot Labs, Mahajan and other founders ran MyMiniLife, a company that Zynga bought in 2009 to gain the underlying technology for online games such as FarmVille. Red Hot Labs was founded in 2012, and received $1.5 million in seed funding from investors including Andreessen Horowitz, Greylock Partners, SV Angel, and General Catalyst Partners.

Google, which is said to have spent more than $23 billion on acquisitions since 2001, kept busy in 2014. It started off the year with a bang, buying Nest Labs for $3.2 billion, a move that gave Xconomy contributing editor Wade Roush pause. Nest Labs makes automated, programmable, WiFi-connected thermostats and smoke detectors.

In May, Google acquired Stackdriver, a two-year-old Boston-based company working on cloud-application monitoring. The search giant added Stackdriver to its cloud platform team. Google followed that by announcing the purchases of satellite imaging company Skybox Imaging and home-monitoring startup Dropcam in June. It acquired Songza, an online music streamer that matches music to your mood, in July.

David Holley is Xconomy's national correspondent based in Austin, TX. You can reach him at dholley@xconomy.com Follow @xconholley